动态条件下电磁轨道炮膛内磁场和电场分析

摘要

针对动态条件下电磁轨道炮膛内磁场和电场分布特性研究缺乏的问题,提出一种数值计算方法.基于磁扩散方程和安培定律,利用测得的动态实验数据和炮尾处磁通密度值,通过有限元计算,确定电枢区域和导轨区域的电流密度值;进一步计算得到电枢前端及后端中轴线各考察点磁场和电场分布特性.结果表明:随着与电枢距离的增加,各考察点峰值磁通密度逐渐减小,电枢前端各点衰减速度远大于后端各点;炮口时刻各考察点峰值电场值为膛内发射过程的数倍.提出的方法能够有效计算轨道炮智能炮弹部位感应电场和磁场,计算结果有助于智能炮弹电磁屏蔽设计.%A numerical computation method is presented for the distribution characteristics of in-bore magnetic and electric fields in electromagnetic railgun under dynamic condition.The measured dynamic test data and the magnetic flux density at the breech end of the railgun are used to calculate the current densities in the armature and rails based on the magnetic diffusion equation and Ampere's law.The distribution characteristics of magnetic field and electric field of the investigated points along the central axes of the armature front end and back end are calculated.The results show that the peak magnetic flux densities of each investigated point decrease gradually with the increase in the distance from point to armature,the decay rate of the investigated point in front of the armature is much larger than that the point behind the armature.The electric field intensity of the investigated point at the muzzle is about several times of that in in-bore launching process.The proposed method can effectively calculate the induced electric field and magnetic field of railgun intelligent ammunition.The calculated results can be used in the electromagnetic shielding design of intelligent ammunition.